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PURPOSE Four-dimensional computed tomography (4D CT) can provide patient-specific motion information for radiotherapy planning and delivery. Motion estimation in 4D CT is challenging due to the reduced image quality and the presence of artifacts. We aim to improve the robustness of deformable registration applied to respiratory-correlated imaging of the(More)
EMPIRE10 (Evaluation of Methods for Pulmonary Image REgistration 2010) is a public platform for fair and meaningful comparison of registration algorithms which are applied to a database of intrapatient thoracic CT image pairs. Evaluation of nonrigid registration techniques is a nontrivial task. This is compounded by the fact that researchers typically test(More)
Current methods of four-dimensional (4D) CT imaging of the thorax synchronise the acquisition with a respiratory signal to restrospectively sort acquired data. The quality of the 4D images relies on an accurate description of the position of the thorax in the respiratory cycle by the respiratory signal. Most of the methods used an external device for(More)
Respiratory motion causes artifacts in slow-rotating cone-beam (CB) computed tomography (CT) images acquired for example for image guidance of radiotherapy. Respiration-correlated CBCT has been proposed to correct for the respiratory motion, but the use of a subset of the CB projections to reconstruct each frame of the 4D CBCT image limits their quality,(More)
Respiratory motion is a major concern in cone-beam (CB) computed tomography (CT) of the thorax. It causes artifacts such as blur, streaks, and bands, in particular when using slow-rotating scanners mounted on the gantry of linear accelerators. In this paper, we compare two approaches for motion-compensated CBCT reconstruction of the thorax. The first one is(More)
Respiratory motion causes artifacts in cone-beam (CB) CT images acquired on slow rotating scanners integrated with linear accelerators. Respiration-correlated CBCT has been proposed to correct for the respiratory motion but only a subset of the CB projections is used to reconstruct each frame of the 4D CBCT image and, therefore, adequate image quality(More)
The cone-beam tomographic projection and the deformation of a discrete volume are problems that have generally been studied separately. They are combined in some applications such as motion compensated algebraic reconstruction. In this paper, we propose two methods to compute the cone-beam projections of a volume deformed with a known motion. The first(More)
In radiotherapy, the respiratory motion of the patient in treatment position is determined from gated cone-beam CT images. This method consists in selecting projections according to a respiratory signal for the reconstruction of a CT image of each respiratory state. This selection can be based on the amplitude or the phase of the signal. The number of(More)
patient que l'on compare à l'image TDM 3D floue, obtenue sans prise en compte du mouvement respiratoire. Abstract and key words To be efficient, the treatement of the lung cancers with radiation therapy must take into account the respiratory motion. The knowledge of this motion requires the acquisition of 4D computed tomography (CT) images. The(More)